# HTML introduction

HTML5 logo

HTML stands for HyperText Markup Language
HTML is a language used to build the content of webpages: browsers know how to interpret HTML so they can show this content when people visit these webpages

# Why HTML?

We want to build content that is displayed correctly in all web browsers and on every device
The content of web pages must be easy to lay out

To make sure every browser is able to interpret HTML and displays content in the same way, standards are required
- The World Wide Web consortium (W3C) sets these standards and browsers are obliged to live by them
- Not only browsers but also webdesigners must follow these standards
- At www.w3.org you can find all standards you can use (as well as those who are in progress)

WARNING

For every webpage you write, you should check whether your HTML code is standard compliant by using the W3C online HTML5 validator!
- See also Tools > Validators > HTML5

The language HTML was created by Tim Berners-Lee in 1991
- The main purpose was to enhance the collaboration between the physics who worked at CERN. They were thinking about new ways of communication and they needed a format (some form of hypertext) to link documents together by using buttons on the screen. Clicking a button simply jumped to another page with other documentation, notes, ...
- This first version of HTML had only 18 elements defined (of which several still exist in HTML5)
A brief history of HTML
- HTML1 (1993)
- HTML2 (1995)
- HTML3 (January 1997)
  - First version published as a W3C recommendation
- HTML4 (December 1997)
- HTML5 (2014 - now)
  - Latest major version of HTML that has been recommended by the W3C
  - Still evolving, new features are regularly implemented